Water-repellent fabric



Patented Mar. 21, 1944 WATER-BEPELLENT FABRIC William J. Thackston, Haddon Heights, N. 1., and Sivert N. Glarum, Ardmore, Pa... auignors to Robin is Haas Company, Philadelphia, Pa, a

corporation of Delaware No Drawing. Application February 14, 1942, Serial No. 430,942

4 Claims.

This invention relates to a composition which imparts to textile fibers, yarns, and fabrics a high degree of water repellency which is retained on laundering or dry cleaning. The invention deals further with the application of the composition to textile materials.

Water repellency imparted to textile materials by waxes or metal soaps from solvent solutions or emulsion has generally a high initial value, but decreases rapidly when the materials are laundered or dry cleaned. This deficiency in retention of water repellency has been lessened, yet not overcome, by multi-bathprocedures and by variations in formulas. Among such variations, it has been proposed that various resins be applied. None of the resins heretofore proposed for this use, however, has imparted to the water-repellent finish the necessary degree of retention of water repellency during the use of treated textile fabric or upon the cleaning thereof.

Improved retention of water repellency is obtained in so-called integral treatment in which a hydrophobic group is reacted with textile fabric. This treatment, on the other hand, is difficult to apply, causes loss in tensile strength, and frequently alters the shades of dyes. Good repellency often disappears on prolonged wear or exposure, even with this type of finish.

An object of this invention is the provision of compositions suitable for imparting to textile fibers, yarns, and fabrics a high initial water repellency and a high degree of retention of repellency. Another object is to produce waterrepellent textile fabrics which retain their repellent nature after wear, exposure, and cleaning. Yet another object is to impart water repellency which is well retained during wear and cleaning and which avoids the difilculties heretofore encountered.

The composition which has been found particularly effective for rendering textile materials water repellent is a water-in-oil emulsion containing a condensate of solvent-soluble urea, formaldehyde, and a monohydric aliphatic alcohol of at least four carbon atoms, solvent-soluble cellulose ether, wax, an aluminum soap, suitable organic solvents, and water. This composition is applied to textile fibers, yarns, or fabrics by immersing, padding, calendering, or otherwise impregnating the textile material, and heating the impregnated material above about 200-F. but below the scorching point of the impregnated material to insolubilize the urea-formaldehydealcohol condensate.

In preparing the water-repellent composition, the active ingredients, condensate, cellulose ether, wax, and aluminum soap, are first taken up in organic solvents to give a formulation which is emulsified with water prior to application to textile material. The proportions of active ingredients found necessary are as follows: organic solvent-soluble urea-formaldehyde-alcohol condensate, 10 to 35 parts; solvent-soluble cellulose ether, 0.1 to 1 part; wax, 5 to 35 parts; and aluminum soap, 5 to 37 parts.

The condensates of urea, formaldehyde, and monohydric aliphatic alcohol are well known in the resin art. In waterproofing textiles, only those condensates are effective which are soluble in organic solvents, such as excess of the alcohol used in the preparation of the condensate, benzene, toluene, solvent naphthas, etc. It is necessary that the alcohol have at least four carbon atoms, as in butanol, hexyl alcohol, capryl alcohol, etc. Condensates of this type are available in concentrated solutions which may be utilized as such or may be diluted with such solvents as butanol, toluene, naphtha, or the like, to any desired concentration. The term urea-formatdehyde-alcohol condensate is used to describe not only those condensates in which urea is the sole resin-forming carbamide, but also condensates based upon the Joint use of urea and such compounds as thio-urea, melamine, thioammeline, and the like.

An additional resin-like material which has been found of considerable value in the compositions of this invention is solvent-soluble cellulose ether, such as ethyl cellulose. This product may be dissolved in a solvent such as toluene or xylene, or in the solution of ureaformaldehyde-alcohol condensate or in a solution of .the other ingredients of the water-repellent "bomposition.

As other necessary ingredients, a water-insoluble wax and an aluminum soap are taken up in organic solvent. Suitable waxes include paraflin, montan wax, beeswax, hydrogenated waxes, etc. The aluminum soap may be the aluminum salt of any long-chained fatty acid, such as oleic, palmitic, stearic, arachidic, cerotic, etc., the hard, higher fatty acids being preferred.

All of the above ingredients are combined in one mixture to give a solvent solution, which may be further extended with a solvent such as an aromatic type of naphtha to yield, when mixed with water, an emulsion oi workable consistency. In mixing solvent solution and water. it is usually helpful to warm the solution, slowly add water, and stir until a homogeneous cream results.

A catalyst for hardening the urea-formaldehyde-condensate may be added to the solvent solution or preferably to the water. As catalysts there may be used small amounts of salts which yield acids, such as ammonium thiocyanate, ammonium phosphate, etc., or acids which will not tender the textile fibers to be treated, such as formic acid or acetic acid.

As a typical example of a composition found suitable for waterproofing, the following preparation is cited. 20 parts of paraflin wax, 20 parts of a petroleum naphtha, and parts of butanol were warmed to 140 F. until the wax was taken up. The mixture was then cooled to 110 F. and 19 parts of aluminum stearate were added, followed by 6 parts of a 10% solution of ethyl cellulose in an aromatic hydrocarbon and 25 parts of a 50% solution of a urea-formaldehyde-butanol condensate in butanol and toluene. This mixture served as a stock paste.

In preparing an emulsion from this stock paste, 76.6 parts of the paste was placed in a mixing tank and stirred, while 104.4 parts of petroleum solvent was mixed therewith. Steam was then blown into the mixture to raise the temperature to 100 F. and a small amount of water was stirred in. There was then diluted with water 2.25 parts of acetic acid (56%), which was added to the mixture. In all, 230.4 parts of water were added.

Various types of cloth were then padded through the above emulsion and squeezed between wood and brass rolls to give a pick up of about 70% of their weight. up of 60% to 120% is satisfactory. The fabrics were then dried on a range dryer, cured at 320 F. for four minutes, washed in a soaper, rinsed, and dried on cans. Some of the fabrics were shrunk on a Palmer machine.

By the above procedure, water repellency was produced in the case of sulfur dyed mercerized 136 x 60, 4 yard broadcloth, a vat dyed mercerized twill, an all-rayon taffeta, a spun rayon and cotton fabric, a rayon warp satin, a mercerized poplin, and other fabrics, with production of high initial repellency and excellent retention of water repellency on cleaning.

All of these treated fabrics had an initial irepellency of 100 on the scale recommended by the American Association of Textile Chemists and Colorists (American Dyestufl' Reporter, vol. 36, No. 1, page P-6, 1941). After three wash tests made according to Federal Specification CCCT- 191A, the repellency varied from 80 to 90 on the above scale, depending upon the construction and type of fabric. Other samples submitted to three dry cleaning tests all gave a repellency value of at least so. It is of interest to note the pieces of the same fabrics treated with long-chained oxymethyl quaternary ammonium salts for integral water repellency gave values of 80 after three standard wash tests and of 70 after three dry cleaning tests.

In a modification of the above procedure, 25 parts of paraflin wax, parts of aluminum stearate, and parts of toluene were warmed together and 10 parts of am] alcohol added thereto. There was then added 2 parts of a xylene solution of ethyl cellulose containing about 02-025 part of this ether and 28 parts of a 50% In general, a pick cerized cotton twill was padded through the above emulsion, squeezed until 65% retention was obtained, dried, and heated at about 300 F. for about 5 minutes. The resulting fabric had a firm,. full hand and exhibited high water repellency, both at the start and after repeated launderings.

When a piece of the above twill was treated with a similar emulsion of wax and aluminum stearate free from the urea-formaldehyde-alcohol condensate but containing the water-soluble urea-formaldehyde condensate, the resulting fabricwas not fully water repellent at the start and completely lost all water repellency after three launderings.

An'emulsion was prepared having the following final composition: 3.7% wax, 3.4% aluminum stearate, 2.3% urea-formaldehyde-butanol conthe boil was between 90 and 100. A sample of fabric soaked in a 10% solution of sodium hydroxide for one hour at room temperature and well rinsed retained its water repellency value of 100, while a piece of the same twill integrally waterproofed dropped in repellency to a value of 80.

Samples of the above twill rendered water repellent with the compositions here disclosed and a sample of integrally waterproofed twill were exposed in a frame to the weather over a period of several weeks. during which time they were subjected to snow, rain, smoke, and sunshine. The two types of samples were then laundered to remove soot and dirt and tested for repellency. The samples made according to this invention had repellency values of 80 and 90, while the integrally treated fabric had a value of 50.

Comparison was also made of the two types of water-repellent twills after abrasion in the Durfee Crockmeter. Waterrepellency values for the toluene-capryl-alcohol solution of urea-formalintegrally treated piece were determined after 25, 50, 75, and 100 cycles to be 50, while the twill finished according to this invention gave values of 90, 85, 80, and 75 after 25, 50, 75, and 100 cycles, respectively. Abrasion resistance was also determined by the T. B.L. abrasion test, which gave a value of 35,000 for the twill treated according to this invention and 24,000 for the integrally treated sample.

A piece of x 80 cotton percale was finished by the method above described in connection with twill. Its intial repellency value was 100, which was retained for two wash tests, dropping to after the third wash test.

An important advantage resulting from the use of the compositions here disclosed is the lack of action on dyes. Many types of waterproofing treatments, particularly those in which amines or quaternary ammonium salts are involved, "throw" certain shades of naphthol dyes, vat dyes, and salt{ colors. Such severe alterations in shade are not encountered with the emulsions of this invention. Another advantage results from the ease with which the disclosed process is carried out. This process is eifective on all types of textile fibers and fabrics, whether of vegetable or animal origin and whether natural or synthetic. I

We claim:

1. A composition suitable for imparting water repellency to textile fibers, yarns, and fabrics which comprises a water-in-oil emulsion containingintheoilphaselotoiispartsofan oraanic solvent-soluble condensate of urea, formaldehyde, and a monohydric aliphatic alcolml of at least four carbon atoms, 0.1 to 1 part of organic solvent-soluble ethyl cellulose, 5 to 35partsofawater-insolublewax,5to37parts of an aluminum soap, and organic solvent therefor.

2. A composition suitable for imparting water repellency to textile fibers, yarns, and fabrics which comprises a water-in-oll emulsion containinginthe oilpha'se10to35partsofacondensate of urea, formaldehyde, and butanol, 0.1 to 1 part of organic solvent-soluble ethyl cellulose,5 to35partsofqaramnwax,5to37parts parts of aluminum stearate, and organic solvent therefor.

8. The process of imparting to textile fabrics a high degree of water repellency which is retained on cleaning, which comprises padding textile fabric through a water-in-oil emulsion containinglntheoilphase loto 35partsofan organic solvent-soluble condensate of urea, formaldehyde, and a monohydric aliphatic alcohol oi at least four carbon atoms, 0.1 to 1 part of organic solvent-soluble ethyl cellulose, 5 to 35 parts of a water-insoluble wax, 5 to 37 parts oi an aluminum soap, and organic solvent therefor, removing excess emulsion from the padded fabric, drying it, and heating it to insolubiiize the condensate thereon.

4. The process of imparting to textile fabrics a high degree of water repellency which is retained on cleaning, which comprises impregnat- 1118 textile fabric with a water-in-oil emulsion contalninglntheoilphaseliltoiiipartsof a condensate of urea, formaldehyde, and butanol, 0,1 to 1 part of organic solvent-soluble ethyl cellulose, 5 to 35 parts of paramn wax, 5 to 37 parts of aluminum stearate, and organic solvent therefor, and heating the impregnated fabric to insoluhilize the condensate thereon.

WILLIAM J. 'macxs'ron. srvm'r N. GLARUM. 

